A204486 Number of (n+2)X4 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly one way, and new values 0..1 introduced in row major order

214, 511, 1189, 2627, 5804, 12861, 28743, 64707, 146082, 330644, 750551, 1704263, 3871635, 8805671, 20024492, 45534930, 103602511, 235678796, 536072298, 1219716427, 2774892264, 6312360407, 14361996073, 32674647931, 74332115679

Offset

1,1

Comments

Column 2 of A204492

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +a(n-2) +10*a(n-3) -6*a(n-4) -10*a(n-5) -17*a(n-6) -3*a(n-7) +23*a(n-8) -3*a(n-9) +37*a(n-10) -19*a(n-11) +26*a(n-12) -48*a(n-13) +4*a(n-14) -19*a(n-15) +21*a(n-16) +a(n-17) +4*a(n-18) -2*a(n-19) for n>29

Example

Some solutions for n=3
..0..0..0..1....0..0..1..0....0..0..1..1....0..1..0..0....0..1..0..0
..1..1..0..1....0..1..0..1....0..1..0..1....0..0..1..1....1..1..1..0
..1..0..1..0....1..1..1..0....0..0..1..0....1..0..0..1....1..0..1..0
..1..0..0..0....0..0..1..1....1..1..0..1....1..1..0..0....0..1..0..1
..1..1..0..1....0..1..0..1....1..1..1..0....0..1..1..0....0..0..1..0

Crossrefs

Sequence in context: A242804 A076159 A258961 * A221807 A200043 A184600

Adjacent sequences: A204483 A204484 A204485 * A204487 A204488 A204489

Keyword

nonn

Author

R. H. Hardin Jan 15 2012

Status

approved